key: cord-0799848-kpo71arb
authors: Zaqout, A.; Daghfal, J.; Alaqad, I.; Hussein, S.; Aldushain, A.; Almaslamani, M.; Abukhattab, M.; Omrani, A. S.
title: The initial impact of a national BNT162b2 mRNA COVID-19 vaccine rollout
date: 2021-04-28
journal: nan
DOI: 10.1101/2021.04.26.21256087
sha: 77ada76e415b0ae812d2b49801f0a0963269dddd
doc_id: 799848
cord_uid: kpo71arb

Objective We herein report the initial impact of a national BNT162b2 rollout on SARS-CoV-2 infections in Qatar. Methods We included all individuals who by 16 March 2021 had completed 14 days of follow up after the receipt of BNT162b2. We calculated incidence rates (IR) and their 95% confidence intervals (CI), during days 1-7, 8-14, 15-21, 22-28, and >28 days post-vaccination. Poisson regression was used to calculate incidence rate ratios (IRR) relative to the first 7-day post-vaccination period. Results We included 199,219 individuals with 6,521,124 person-days of follow-up. SARS-CoV-2 infection was confirmed in 1,877 (0.9%), of which 489 (26.1%) were asymptomatic and 123 (6.6%) required oxygen support. The median time from the first vaccination to SARS-CoV-2 confirmation was 11.9 days (IQR 7.7-18.2). Compared with the first 7-day post-vaccination period, SARS-CoV-2 infections were lower by 65.8-84.7% during days 15-21, days 22-28, and >28 days (P <0.001 for each). For severe COVID-19, the incidence rates were 75.7-93.3% lower (P <0.001 for each) during the corresponding time periods. Conclusion Our results are consistent with an early protective effect of BNT162b2 against all degrees of SARS-CoV-2 severity.

confirmation was 11.9 days . Compared with the first 7-day post-vaccination 48 period, SARS-CoV-2 infections were lower by 65.8-84.7% during days 15-21, days 22-28, 49 and >28 days (P <0.001 for each). For severe COVID-19, the incidence rates were 75.7-50 93.3% lower (P <0.001 for each) during the corresponding time periods. 51

Our results are consistent with an early protective effect of BNT162b2 against all degrees of 53 SARS-CoV-2 severity. 54 All rights reserved. No reuse allowed without permission.

(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted April 28, 2021. ; https://doi.org/10.1101 https://doi.org/10. /2021 Background 55 A two-dose regimen of BNT162b2, the Pfizer-BioNTech COVID-19 mRNA vaccine, was 56 shown to reduce the risk of SARS-CoV-2 by around 95% in a randomized clinical trial, and 57 in a mass national vaccination program.[1, 2] On 23 December 2020, Qatar started a national 58

BNT162b2 rollout programme, in addition to existing COVID-19 public health control 59 measures. The rollout initially prioritised healthcare workers, individuals aged ≥50 years, and 60 those with chronic or immune suppressive medical conditions. We herein report the initial 61 impact of BNT162b2 on SARS-CoV-2 infections in Qatar. 62 We calculated SARS-CoV-2 infection incidence rates (IR), and their 95% confidence 72 intervals (CI), per 100,000 person-days during five time-period: days <7 days, 8-14 days, 73 15-21 days, 22-28 days, and >28 days from receipt of the first BNT162b2 dose. Individuals 74 stopped contributing person-days once SARS-CoV-2 infection was confirmed or at the study 75 end date, whichever came first. We used Poisson regression to calculate incidence rate ratios 76 (IRR) and their 95% CI for the latter four time-periods relative to IR during the first seven 77 days from the first BNT162b2 dose. Statistical analyses were performed using Stata 78 Statistical Software, Release 16.1 (StataCorp., College Station, Texas). 79 All rights reserved. No reuse allowed without permission.

(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted April 28, 2021. ; https://doi.org/10.1101/2021.04.26.21256087 doi: medRxiv preprint

The included 199,219 individuals contributed 6,521,124 person-days of follow up. SARS-81

CoV-2 infection was confirmed in 1,877 (0.9%), of which 365 (19.5%) occurred after receipt 82 of a second BNT162b2 dose. The median time from first vaccination to SARS-CoV-2 83 confirmation was 11.9 days (IQR 7.7-18.2). Compared with those without SARS-CoV-2 84 infection, infected individuals were significantly older, and more likely to have co-existing 85 medical conditions (Table) . Cough (1,018, 54.2%) and fever (745, (Figure) . 102

Our findings are consistent with those shown previously in a community setting and in 103 healthcare workers, but our report is the first to include an entire national cohort of 104 All rights reserved. No reuse allowed without permission.

(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted April 28, 2021. ; https://doi.org/10.1101/2021.04.26.21256087 doi: medRxiv preprint BNT162b2 recipients. [2, 4] We also demonstrated a significant reduction in risk of severe 105 COVID-19. This is particularly important, given its potential to reduce COVID-19-associated 106 morbidity and mortality, and decrease its impact on healthcare resource utilization.

[5] 107

We found relatively high SARS-CoV-2 IR during the first two weeks following receipt of the 108 first BNT162b2 dose. While the vaccine's protective effect may not be apparent during the 109 first two weeks after BNT162b2 vaccination,[1] recipients may wrongly perceive themselves 110 to be at a reduced risk of SARS-CoV-2 infection and become less adherent to 111 nonpharmacological preventive measures such as social distancing and face covering. The limitations of this study include its observational nature and the lack of a non-vaccinated 126 control group. We used the first 7-day post-vaccination period, during which no vaccine 127 effectiveness is expected, as a reference to assess the vaccine's protective benefits in later 128 time-periods. Overall, our results are consistent with an early protective effect of BNT162b2 129 All rights reserved. No reuse allowed without permission.

(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.

The copyright holder for this preprint this version posted April 28, 2021. ; https://doi.org/10.1101 https://doi.org/10. /2021 against all degrees of SARS-CoV-2 severity. It is anticipated that, in addition to ongoing 130 nonpharmacological interventions, broader vaccine coverage will contribute to the national 131 and global pandemic control efforts. 132

The study was approved by Hamad Medical Corporation's Institutional Review Board with a 134 waiver of informed consent (MRC-01-21-207). 135 (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. 

Chronic lung disease

Data are presented as number (%) or median (interquartile range). P values were derived from Pearson's chi-206 squared or Wilcoxon rank-sum test, as appropriate

The authors declare no conflict of interests in relation to this manuscript. 137Funding 138The publication of this report was funded by Qatar National Library. No other funding was 139 required. 140

We would like to thank Hussam Alsoub and Faraj S. Howady for their support during the 142 preparation of this report. 143 (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. Pfizer and BioNTech. Pfizer and BioNTech confirm high efficacy and no serious 174 safety concerns through up to six months following second dose in updated topline 175 analysis of landmark COVID-19 vaccine study. https://www.pfizer.com/news/press-176 release/press-release-detail/pfizer-and-biontech-confirm-high-efficacy-and-no-serious 177 (accessed 10 Apr 2021). 178 All rights reserved. No reuse allowed without permission.

(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.The copyright holder for this preprint this version posted April 28, 2021. ; https://doi.org/10.1101 https://doi.org/10. /2021 All rights reserved. No reuse allowed without permission.(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.The copyright holder for this preprint this version posted April 28, 2021. ; https://doi.org/10.1101 https://doi.org/10. /2021